The invention relates to a high-frequency excited high-power laser comprising two resonator mirrors having resonator mirror surfaces arranged opposite one another, a gas discharge chamber located between the resonator mirror surfaces, a waveguide extending between these resonator mirror surfaces and having two reflecting waveguide surfaces located opposite one another and facing the gas discharge chamber, and a beam path having an initial bundle of waves, this initial bundle expanding for its part towards the second mirror surface in an initial direction extending at right angles to a region of the first mirror surface and, due to multiple back and forth reflection between the second and the first mirror surfaces, expanding with spatial coherence as a wave bundle system between the waveguide surfaces in a transverse direction extending at right angles to the initial direction.
A high-frequency excited high-power laser of this type is known from EP-A-0 305 893.
In this laser, formation of the wave bundle system is brought about, proceeding from the initial wave bundle, as a result of the mirror surfaces being formed, for example cylindrically curved, in accordance with the mirror surfaces of an instable laser resonator.
The waveguide, on the other hand, comprises waveguide surfaces extending in two planes running parallel to one another. These waveguide surfaces reflect the beams on, without a change in direction, in the direction in which they are reflected by the resonator mirror surfaces.
The production and adjustment of the resonator mirror surfaces as mirror surfaces of an instable resonator gives rise to problems and can be complicated.
For this reason, the object underlying the invention is to improve a high-power laser of the generic type such that for forming the wave bundle system, proceeding from the initial wave bundle, an arrangement of the resonator mirror surfaces as those of an instable resonator is not absolutely imperative but that the expansion of the wave bundle system with spatial coherence in the transverse direction at right angles to the initial direction can be achieved by other means.